Problem : 2NO2(g)→2NO(g) + O2 Calculate the change in enthalpy for this equation given the following two heats of formation:


  δHfNO2(g) = 33.85 kJ / mole  
  δHfNO(g) = 90.37 kJ / mole  


δH=δHf(products) - δHf(reactants)  
 =(2 moles×(90.37 kJ / mole) + 0 kJ / mole) - (2×33.85 kJ / mole)  
 =113.04 kJ